For many years, gas valve assemblies have had safety valves and manually controlled valves connected in series with a thermostatically controlled valve, whether it be a pressure operator or an electromechanically operated valve. The manual control valves have generally been of the plug type which are very expensive to manufacture and the valve assembly is quite bulky. Additionally, with the advent of electronic ignition and the need for more safety with gas valve assemblies, the industry has highly recommended that a dual valve be used for the automatic control to ensure that when the automatic control is in the off condition, positive shut off is assured. Such dual valve requirement additionally adds to the cost of the gas valve assembly. Such gas valve assemblies have been sold by Honeywell Inc. as the V800, VR800, and V8280, one type assembly is shown in the Instruction Sheet #60-2019-4, published July 1979 by Honeywell Inc.
The present invention is concerned with a gas valve assembly having a safety valve and an automatically controlled valve connected in series with a single manual operator or knob to control the operation of the safety valve and the automatically controlled valve. Specifically, when the manual control is in a first position ("pilot"), the safety valve can be controlled and the electromechanically controlled automatic valve is rendered inoperative. When the manual control is in a second position ("on"), the electromechanically controlled valve can be operated. More specifically, the plunger of the automatically controlled valve is moved by the energization of an electric coil in response to the automatic control signal. When the manual control is in the first position ("pilot"), a pin is positioned against the plunger to limit its movement and maintain the automatically controlled valve in an off position.